In this study, the methods to identify the causes of electrical fires are suggested. Among several causes of electrocal fires, it is focused upon a short-circuit and an over-current accidents, which take the highest ratio compare with any other causes. To propose the exact method of identification, electric wires(HIV, IV), fuses and plug-receptacls are tested under the conditions of electrical accidents and external fires, respectively. By analyzing the microphotographs, the differences between the results from electrical fires and the others are found out.